As someone mentioned, there is a difference between prerecorded lessons online, and live video lessons. I give flamenco guitar lessons via live Skype, and many of my students are classical guitarists. Who by the way, learn flamenco very easily because - assertions to the contrary notwithstanding - there is practically no difference between basic classical guitar technique and basic flamenco guitar technique.
As Alan Green pointed out though, you don't just "pick up" flamenco. It requires dedicated study.
Classical and Flamenco guitar lessons via Skype worldwide - Classical and Flamenco guitars from Spain